1. Field of the Invention
The present invention relates to liquid droplet jetting apparatuses for jetting liquid droplets.
2. Description of the Related Art
In conventional liquid droplet jetting apparatuses for jetting liquid droplets, there are many liquid droplet jetting apparatuses each of which is provided with a waste liquid recovery device recovering an unnecessary liquid (hereinafter referred to also as “waste liquid”) discharged for example during maintenance for the liquid droplet jetting head. Each of the waste liquid recovery devices of general type has a waste liquid case and an absorber (absorbing member) which is formed of a porous material, which is accommodated in the waste liquid case and which absorbs the waste liquid.
Among them, Japanese Patent Application Laid-Open No. 08-104014 discloses an ink jet recording apparatus including a means (a full liquid detection means) for detecting a full liquid state of the absorber. In more detail, it is configured such that the absorber (ink absorbing member) is accommodated in the waste liquid case (waste ink recovering container), and that a pair of electrodes are provided to the waste liquid case at a portion (where ink reaches last) away from a portion from which waste liquid flows into the waste liquid case (liquid intake portion). The full liquid state is detected by detecting conduction between the electrodes when the waste liquid has reached the portion at which the pair of electrodes are provided.
However, when the liquid droplet jetting apparatus uses two or more types of liquids, in order to prevent mixture of different types of liquids, etc., it is sometimes configured not to send two types of waste liquids collectively to the waste liquid case, but to send them through different routes to the waste liquid case, respectively. In this case, these two types of waste liquids permeate respectively into different parts of the absorber from two liquid intake portions provided respectively in the waste liquid case.
According to the above configuration, when adopting the method for detecting a full liquid state of the absorber with electrodes provided in the absorber at a predetermined detection position as in the ink jet recording apparatus disclosed in the Japanese Patent Application Laid-Open No. 08-104014, the two types of waste liquids scarcely reach the detection position at the same time, but usually reach there one after the other. In such cases, even if the absorber is determined to be fully permeated as only one liquid has reached the detection position, since the other liquid has not yet actually reached there, there is still room in the absorber (portions having not yet absorbed liquids). That is, although the absorber can actually absorb more waste liquids, it is falsely determined to be fully permeated, thereby decreasing the efficiency of absorbing waste liquids.